It is known, for example from U.S. Pat. No. 4,598,011, U.S. Pat. No. 5,032,445, U.S. Pat. No. 5,093,179 and U.S. Pat. No. 8,556,990 to provide a reinforced PTFE membrane to assist in the growth of bone and tissue after trauma and surgery. The membrane acts as a barrier to prevent rapidly migrating connective tissue cells from entering a bone defect so that slower migrating cells with osteogenic potential can preferentially enter the bone defect and assist with bone growth.
For example, U.S. Pat. No. 8,556,990 discloses a reinforced PTFE membrane. According to that disclosure a portion of a bone defect is covered with a multilayered membrane that includes a reinforcing layer. A member of the reinforcing member is fastened to an area of bone and soft tissue is secured about the membrane. The membrane facilitates healing of the defect and/or otherwise improves a bone surface. One membrane comprises a plurality of layers that includes a binding layer and a PTFE layer which has a textured surface and a substantially smooth surface. The textured surface provides a top surface of the membrane and the substantially smooth surface contacts bone. According to U.S. Pat. No. 8,556,990, the reinforcing member is a titanium member provided with “fingers” which provide the necessary reinforcement.
The present invention, at least in its preferred embodiments seeks to provide an alternative construction of a reinforced surgical membrane.